textproduct: Rapid City

KEY MESSAGES

-Snow tapers off this morning with additional accumulations of 1 to 2 inches across northwestern SD.

-Very cold temperatures today with highs in the teens to 20s and lows below zero.

-Rapid warm up Sunday with temps reaching the upper 50s to low 60s in parts of the Black Hills and adjacent foothills

-Warm and dry the first half of next week with active weather and fluctuating temps after

DISCUSSION

(Today Through Friday) Issued at 224 AM MST Sat Dec 13 2025

Current upper air analysis and water vapor imagery shows the Northern Plains under active and moisture-laden northwest flow. Area of modest mid-level FGEN has set up across the CWA, supporting a band of light to moderate snow across northwestern SD and portions of northeastern WY. Sfc temps across the CWA are cold, ranging from near zero across northwestern SD to the teens and low 20s across northeastern WY into southwestern SD.

Snow will continue through early this morning, mainly across northwestern into central SD where additional accumulations of 1 to 2" expected. Additional accumulations elsewhere across western SD into northeastern WY are expected to be light, generally less than an inch. The bulk of the lift/fgen should move further south of the CWA by this afternoon with snow tapering off across much of the area by noon. A few snow showers will still be possible across southwestern SD this afternoon, but not expecting much in terms of accumulation.

Cold air will remain in place through this evening into the overnight hours. High temperatures today will be in the single digits across northwestern SD and in the low 20s across northeastern WY into the Black Hills and southwestern SD. Another frigid night in store for western SD where temperatures of near to below zero expected, especially across northwestern into south central SD. Wind chills in these areas will drop to the negative teens to 20 below in some spots.

Temperatures rebound dramatically on Sunday as upper level ridge builds in the western US and south-southwesterly return flow supports strong WAA. By Sunday afternoon, H85 temps progged to reach 15 to 20C which will support highs in the mid to upper 50s across the BH, northeastern WY, and southwestern SD. Existing snowpack may temper highs somewhat but expect a much warmer day for Sunday. Warming trend and dry weather continues through the beginning of next week under the influence of the western US ridge. Deterministic guidance in good agreement of aforementioned ridge flattening out by the mid week, bringing the Northern Plains back under the influence of the active northern stream and semi- westerly flow. The latter half of next week looks to be unsettled as several shortwaves progressing through the flow impact the region.

AVIATION

(For the 18Z TAFS Through 18Z Sunday) Issued At 1029 AM MST Sat Dec 13 2025

Areas of MVFR conditions due to low clouds/snow will continue to diminish through 21Z. Mainly VFR conditions are expected across the forecast area after 21-23Z.

UNR WATCHES/WARNINGS/ADVISORIES

SD...None. WY...None.